Different exercise intensity alleviates fear memory generalization in PTSD mice by promoting adiponectin mediated adult hippocampal neurogenesis.

AIM: To explore the intensity-dependent effects of exercises to alleviate fear memory generalization in post-traumatic stress disorder (PTSD) and the underlying mechanism. METHODS: Male C57 BL/6J mice were randomly divided into the control group, PTSD group, high-intensity exercise (PTSD-High) group, and low-intensity exercise (PTSD-Low) group. PTSD model were created via using a combination of conditioned foot shock(CF) and single-prolonged stress (SPS). The contextual fear test was used to test the mice's ability to discriminate safety situations from fear condition. Immunofluorescence observed and quantified the newborn immature neurons in the DG area of the mice's hippocampus. ELISA was used to determine the secretion level of serum tissue adiponectin. RESULTS: (1) The immobility times for the PTSD-High and Control groups were significantly lower than those of the PTSD group. (2) Immunofluorescence analysis showed that the cell density, dendritic branching points and length of newborn immature neurons were elevated in High and Low groups compared to the PTSD group. (3) Adiponectin levels in the serum of the control and PTSD High group were significantly higher than those in the PTSD group and PTSD-Low group. CONCLUSION: Fear memory establishment in PTSD mice is associated with decreased hippocampal neurogenesis. High-intensity exercise ameliorated fear memory by enhancing adiponectin secretion and promoting hippocampal neurogenesis. High-intensity exercise exerted better improvement of brain functions to PTSD model. [ABSTRACT FROM AUTHOR]